IntroductionThe
Due is the latest creation from Gallo Acoustics, a company famous for
making physically round AV speakers. The $599 Due’s name is derived
from the fact that the speaker contains two spherical units, rather
than the single sphere of past Gallo designs. The two spheres are
joined in the middle by a cylindrical tweeter assembly that is unique
to Gallo, resulting in a very stylish “un-speakerlike” speaker. Gallo
paired the Due with their $750 MPS-150 woofer for low frequency
reinforcement. This woofer is also very unconventional in design. The
design features two short cylinders, one housing the 10-inch driver,
the other containing a 240-watt amplifier and related electronics.

The Dues are refreshingly small, measuring 11 inches tall, five inches
wide and five inches deep. The Dues come with modernistic perforated
steel grilles that can easily be removed. Removing the grilles leaves
the speakers almost an inch thinner and reveals their unique dual
spherical shape, making the speakers look even smaller. If the look of
the Dues sans metal grilles isn’t to your taste, you can use the
Gallo-supplied black fabric grilles for the four-inch drivers. The Due
also comes with a simple yet elegant stand that allows them to be
positioned either horizontally or vertically on a shelf. Gallo also
offers their Wallflower stand, which raises the Due to listening height
from the floor. This color-matched stand complements the Due’s styling
with its single curved tube stemming up from a heavy oval base. This
diminutive speaker’s frequency range is 60 Hz to 40 kHz and is highly
efficient at 91 dB.

Each sphere features a four-inch driver, custom made for Gallo. The
spherical enclosure, with no parallel surfaces, is inherently strong,
reducing unwanted resonance. The Due utilizes Gallo’s S2 technology to
increase the volumetric efficiency of the enclosure, making it appear
bigger to the drivers than it really is. According to Gallo, the
typical volumetric efficiency of most enclosures is between one and two
– the Due enclosure with Gallo’s S2 technology has a volumetric
efficiency of 10. The S2 technology utilizes a shredded polyolefin
material suspended in a fine mesh that couples to the driver at lower
frequencies. The added mass provides greater control of the driver and
increased efficiency for greater dynamic range.

The
four-inch drivers are separated by Gallo’s unique C.D.T. tweeter.
“C.D.T.” stands for Cylindrical Diaphragm Tweeter. The C.D.T. is, of
course, cylinder-shaped, providing an extremely wide dispersion pattern
of 120 degrees. The tweeter is made out of a silver coated Kynar
(high-tech plastic) diaphragm, with silver wires attached to each end.
This assembly is wrapped around a polypropylene core that absorbs the
driver’s backwave. The current is passed across the face of the driver,
causing it to expand and contract, a technology similar to the piezo
tweeters of yesteryear.

The C.D.T.’s surface area is more
than 12 times that of a conventional one-inch dome tweeter. Despite the
large surface area, the moving mass weight is lower than that of most
conventional drivers, as there are no voice coils, formers or
surrounds. The design allows for a great deal of output without breakup
or distortion and also greatly contributes to the speakers’ large sweet
spot.

The MPS-150 subwoofer is made of two similarly-sized components, each
measuring 5.5 inches high with an 11-inch diameter. One enclosure holds
a custom-made 10-inch driver. It is connected to the other enclosure
with a single quarter-inch phono plug-tipped cable. The second
enclosure holds a 240-watt class A/B amplifier. The amplifier enclosure
features a recessed area with both high and low level inputs and
outputs, control knobs for crossover level, continuous phase adjustment
and relative volume. Also on this panel are a standard IEC power cord
connector and power switch with positions for on, off and auto.

Set-up
I first set the Dues up in my two-channel system. I placed the Dues on
the optional Wallflower stands. I positioned the stands six feet apart
and two feet from the front wall, with the Dues facing straight ahead.
The MPS-150 was fed via its low-level input. My source unit is a Theta
Data Basic CD Transport, feeding a Perpetual Technologies DSP/DAC
combination. The Krell 300iL integrated amplifier provided
amplification.

The Gallo speakers were ridiculously easy to set up. Everything was
straightforward, making the clear instructions practically unnecessary.
The Dues’ stands, both Wallflower and desktop, were easily assembled. I
found the four-inch drivers needed a long break-in period, so I let
them play nonstop for one week before I did any serious listening.